Add [[nodiscard]] to expected<T, E>

Summary: We already had a bug around it. Differential Revision: D68917072 fbshipit-source-id: 49760d62247e14a348cc37ec0c0f32f8cf21e4e8
facebook · Jan 31, 2025 · 58ad784 · 58ad784
1 parent 2cf5bc3
commit 58ad784
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Showing 2 changed files with 3 additions and 2 deletions.
diff --git a/third-party/thrift/src/thrift/compiler/whisker/expected.h b/third-party/thrift/src/thrift/compiler/whisker/expected.h
@@ -53,7 +53,7 @@ namespace whisker {
  *     - transform_error
  */
 template <typename T, typename E>
-class expected;
+class [[nodiscard]] expected;
 
 /**
  * A type that mimics std::unexpected<E>:

diff --git a/third-party/thrift/src/thrift/compiler/whisker/test/expected_test.cc b/third-party/thrift/src/thrift/compiler/whisker/test/expected_test.cc
@@ -274,7 +274,8 @@ TEST(ExpectedTest, emplace_never_empty) {
       throw std::runtime_error("throw_on_construct");
     }
   };
-  EXPECT_THROW((expected<throw_on_construct, int>()), std::runtime_error);
+  EXPECT_THROW(
+      (std::ignore = expected<throw_on_construct, int>()), std::runtime_error);
   expected<throw_on_construct, int> e = unexpected(1);
   EXPECT_EQ(e.error(), 1);